Sciencemadness Discussion Board

Calcium nitrate via NH4NO3

Chemistry Alchemist - 11-11-2011 at 23:17

I may be planning on making Calcium nitrate with Ammonium nitrate and calcium hydroxide... Would these react at room temperature or only at elevated temperatures? all the other hydroxides are soluble so they react at room temp but because of the extremely low solubility of the Calcium hydroxide will it still react at room temp or would i need to boil to get the reaction started?

Ca(OH)<sub>2</sub> + NH<sub>4</sub>NO<sub>3</sub> = Ca(NO<sub>3</sub>;)<sub>2</sub> + NH<sub>4</sub>OH

blogfast25 - 12-11-2011 at 05:28

Calcium hydroxide is far, far from 'extremely insoluble': if it was your reaction couldn't proceed at all. Shaling water with Ca(OH)2 gives 'lime water', used for testing for CO2 (Ca(OH)2 + CO2 === > CaCO3 + H2O)

Boiling just speeds it up a bit. You'll end up with a bit of a mess though: a mixtue of Ca(NO3)2, some 'NH4OH', some dissolved Ca(OH)2, some NH4NO3. Isolating Ca(NO3)2 from it is nigh impossible.

Instead dissolve limestone in dilute nitric acid: CaCO3 + 2 HNO3 === > Ca(NO3)2 + CO2 + H2O. Or dissolve slaked lime (Ca(OH)2) in dilute nitric acid.

Chemistry Alchemist - 12-11-2011 at 07:49

Yeah i don't have any Nitric acid on me right now but i may be planning to use some of my Potassium nitrate to make nitric acid... now for the Calcium nitrate, i boiled the 2 chemicals, Ammonia was released and most of the hydroxide dissolved except for the bits that went in as a clump... the ammonia may of been from the Ammonium nitrate decomposing but i didn't see any NO<sub>2</sub> being imitated so im guessing i may have a cude solution of the stuff... ill filter off the insoluble hydroxide and just boil it down until powder forms and just cool it down to crystallize some to form a pure product (by the looks of my solution its a bit beige)

ldanielrosa - 12-11-2011 at 21:13

Wow, you're going the opposite direction from me. Around here the gov't made it more troublesome to get ammonium nitrate, but calcium nitrate is plentiful and cheap in a fairly good grade.

I find that Ca(NO3)2 is a good nitrate source for any soluble sulfate or carbonate. I'm using it to make ammonium nitrate, copper nitrate, manganese nitrate (this one isn't coming out so well...), and cobalt nitrate.

Chemistry Alchemist - 12-11-2011 at 21:44

I use ammonium nitrate for sodium nitrate and potassium nitrate... Magnesium nitrate is good for making sodium and potassium as we... Haven't found a way to make copper nitrate yet other then using nitric acid... My ammonium nitrate is daily pure... Tho recently when I opened to cool packs, the NH<sub4>4</sub>NO<sub4>3</sub> was a bit damp but other then that, haven't had any bad ammonium nitrate

sternman318 - 12-11-2011 at 23:27

Quote: Originally posted by Chemistry Alchemist  
.the ammonia may of been from the Ammonium nitrate decomposing but i didn't see any NO<sub>2</sub> being imitated so im guessing i may have a cude solution of the stuff

I believe the decomposition product of AN is nitrous oxide, not nitrogen dioxide.

[Edited on 13-11-2011 by sternman318]

Random - 13-11-2011 at 02:25

What about mixing bigger amount of Ca(OH)2 along with NH4NO3 crystals and adding a small amount of water? Some water should form from the reaction, while most of the ammonia will be released as a gas due to smaller amounts of water. Then saturating with CO2 should precipitate Ca(OH)2 in the solution as CaCO3. Some ammonium carbonate could be still present in the solution though.